Evaluation of a carbonate reservoir. A case study by using seismic data and well data.

Estimation of reservoir properties and facies from seismic data is a well-established technique, and there are numerous methods in common usage. Our 1D stochastic inversion process (ODiSI), based on matching large numbers of pseudowells to color-inverted angle stacks, produces good estimations of reservoir properties, facies probabilities, and associated uncertainties. Historically, ODiSI has only been applied to siliciclastic reservoir intervals. However, the technique is equally suited to carbonate reservoirs, and ODiSI gives good results for the Mishrif Reservoir interval in the Rumaila Field in Iraq. Of course, a thorough awareness of the quality of all input well data and detailed validation of the parameters input to the inversion process is crucial to understanding the accuracy of the results.

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Understanding the fracture role on hydrocarbon accumulation and distribution using seismic data: A case study on a carbonate reservoir from Iran

Journal of Applied Geophysics ◽

10.1016/j.jappgeo.2013.06.015 ◽

2013 ◽

Vol 96 ◽

pp. 98-106 ◽

Cited By ~ 9

Author(s):

Sadegh Karimpouli ◽

Hossein Hassani ◽

Alireza Malehmir ◽

Majid Nabi-Bidhendi ◽

Hossein Khoshdel

Keyword(s):

Seismic Data ◽

Carbonate Reservoir ◽

Hydrocarbon Accumulation

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Application of geophysical methods in the extrapolation of sedimentological data on unmastered areas of deposits (on the example of Pennsylvanian carbonate reservoir, Akanskoye oilfield, east of Russian Platform)

Proceedings of OilGasScientificResearchProjects Institute SOCAR ◽

10.5510/ogp2021si200564 ◽

2021 ◽

pp. 128-134

Author(s):

B. V. Platov ◽

◽

A. N. Kolchugin ◽

E. A. Korolev ◽

D. S. Nikolaev ◽

...

Keyword(s):

Seismic Data ◽

Geophysical Methods ◽

Russian Platform ◽

Carbonate Reservoir ◽

Reservoir Properties ◽

Reservoir Characteristics ◽

The North ◽

Study Results ◽

Core Study ◽

Well Data

A feature of the oil-bearing carbonate deposits of the lower Pennsylvanian in the east of the Russian platform is their rapid vertical and horizontal change. It is often difficult to make correlations between sections, especially in the absence of core data when using only geophysical data. In addition, not all facies are reliably identified and traceable from log data and not all have high reservoir properties. Authors made an attempt to trace the promising facies both to adjacent wells and, in general, to the entire field area using core study results and translation of these results using log and seismic data. The data showed pinching of rocks with high reservoir characteristics in the direction of the selected profile (from south to north within the field). Coastal shallow water facies, represented by Grainstones and Packstones, with high reservoir properties in the south of the field, are replaced by lagoon facies and facies of subaerial exposures, represented by Wakestones and Mudstones with low reservoir characteristics, in the north of the field. The authors suggest that this approach can be applicable for rocks both in this region and for areas with a similar structure. Keywords: pinch-out; well data; seismic data; limestone; facies; reservoir rocks.

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Seismic integrated study for offshore deep- and thin-stratum characterization: A case study from the Enping sag within the Pearl River Mouth Basin

The Leading Edge ◽

10.1190/tle39030176.1 ◽

2020 ◽

Vol 39 (3) ◽

pp. 176-181

Author(s):

Jun Liu ◽

Donghai Liang ◽

Guangrong Peng ◽

Xiaomin Ruan ◽

Yingwei Li ◽

...

Keyword(s):

Seismic Data ◽

River Mouth ◽

Rock Physics ◽

Pearl River ◽

Pearl River Mouth Basin ◽

Avo Inversion ◽

Lithology Prediction ◽

The Pearl River ◽

Well Data

In the Enping 17 sag within the Pearl River Mouth Basin in the South China Sea, one wildcat well has been drilled to the Lower Paleogene Enping Formation (FM EP) and partially into the Wenchang Formation (FM WC) for deep formation hydrocarbon exploration. However, no commercial play was discovered. The reasons for this are clear if the petroleum systems modeling is examined. In FM EP, the main reason for failure is due to poor sealing. In FM WC, the failure is due to the lack of a good reservoir for hydrocarbon accumulation. Encountering a 9 m thick reservoir at a depth of 4650 m indicates that braided fluvial delta and lowstand turbidite sandstone may develop in FM WC. With the objective of establishing cap rock in FM EP and reservoir rock in FM WC, and in the absence of sufficient well data, an integrated framework for 3D seismic reservoir characterization of offshore deep and thin layers was developed. The workflow includes seismic data reprocessing, well-log-based rock-physics analysis, seismic structure interpretation, simultaneous amplitude variation with offset (AVO) inversion, 3D lithology prediction, and geologic integrated analysis. We present four key solutions to address four specific challenges in this case study: (1) the application of adaptive deghosting techniques to remove the source and streamer depth-related ghost notches in the seismic data bandwidth and the relative amplitude-preserved bandwidth extension technique to improve the seismic data resolution; (2) a practical rock-physics modeling approach to consider the formation overpressure for pseudoshear sonic log prediction; (3) interactive and synchronized workflow between prestack 3D AVO inversion and seismic processing to predict a 9 m thick layer in FM WC through more than 60 rounds of cyclic tests; and (4) cross validation between seismic qualitative attributes and quantitative inversion results to verify the lithology prediction result under the condition of insufficient well data.

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Drilling success as a result of probabilistic lithology and fluid prediction—a case study in the Carnarvon Basin, WA

The APPEA Journal ◽

10.1071/aj07004 ◽

2008 ◽

Vol 48 (1) ◽

pp. 31 ◽

Cited By ~ 4

Author(s):

Matthew Lamont ◽

Troy Thompson ◽

Carlo Bevilacqua

Keyword(s):

Seismic Data ◽

Rock Physics ◽

Geological Model ◽

Probabilistic Prediction ◽

Individual Probability ◽

Fluid Properties ◽

Lithology Prediction ◽

Well Data ◽

Carnarvon Basin

The aim of quantitative interpretation (QI) is to predict lithology and fluid content away from the well bore. This process should make use of all available data, not well and seismic data in isolation. Geological insight contributes to the selection of meaningful seismic attributes and the derivation of valid inversion products. Uncertainty must be taken into account at all stages to permit risk assessment and foster confidence in the predictions. The use of the Bayesian framework enables prior knowledge, such as a geological model, to be incorporated into a probabilistic prediction, which captures uncertainty and quantifies risk. Nostradamus is a fluid and lithology prediction toolkit that forms part of a comprehensive QI workflow. It utilises a Bayesian classification scheme to make quantitative predictions based upon inverted seismic data and depth-dependent, stochastic rock physics models. The process generates lithology and fluid probability volumes. All available information is combined using geological knowledge to create a realistic pre-drill model. Separately, stochastically modelled multidimensional crossplots, which account for the uncertainty in the rock and fluid properties (based on petrophysical analyses of well data), are used to build probability density functions such as acoustic impedance (AI) vs Vp/Vs and LambdaRho vs MuRho. These are then compared to crossplots of equivalent inverted data to make predictions and quantitatively update the geological model. Individual probability volumes as well as a most-likely lithology and fluid volume are generated. This paper presents a case study in the Carnarvon Basin that successfully predicts fluids and lithologies away from well control in a way that effectively quantifies risk and reserves. Two of the three successful gas exploration wells were drilled close to dry holes.

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